The total number of valence electrons in 4.2g of ion is (NA is the Avogadro's number)
1. 2.1NA
2. 4.2NA
3. 1.6NA
4. 3.2NA
When 22.4L of H2(g) is mixed with 11.2L of Cl2(g) each at STP, the moles of HCl(g) formed is equal to
1. 1 mole of HCl(g)
2. 2 moles of HCl(g)
3. 0.5 mole of HCl(g)
4. 1.5 moles of HCl(g)
The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (at. mass of Al = 27)
1. 180 kg
2. 270 kg
3. 540 kg
4. 90 kg
In the Haber process, 30 L of dihydrogen and 30 L of dinitrogen were taken for the reaction, which yielded only 50% of the expected product. The composition of the gaseous mixture under the said conditions at the end is:
1. 20 L ammonia, 10 L nitrogen, 30 L hydrogen
2. 20 L ammonia, 25 L nitrogen, 15 L hydrogen
3. 20 L ammonia, 20 L nitrogen, 20 L hydrogen
4. 10 L ammonia, 25 L nitrogen, 15 L hydrogen
What is the approximate number of atoms present in 4.25 grams of NH3?
1. 4 x 1023
2. 2 x 1023
3. 1 x 1023
4. 6 x 1023
In the reaction, 4NH3(g)+ 5O2(g) 4NO(g) +6H2O(l)
When 1 mole of ammonia and 1 mole of O2 reacts to completion, then:
1. | 1.0 mole of H2O is produced. |
2. | 1.0 mole of NO will be produced. |
3. | All the oxygen will be consumed. |
4. | All the ammonia will be consumed. |
An element X has the following isotopic composition,
200X : 90%, 199X : 8.0%, 202X : 2.0%
The weighted average atomic mass of the naturally occurring element X is closest to:
1. | 205 u | 2. | 220 u |
3. | 196 u | 4. | 200 u |
0.24g of a volatile gas, upon vaporisation, gives 45 mL vapour at NTP. What will be the vapour density of the substance?
(Density of H2 = 0.089)
1. 95.93
2. 59.93
3. 95.39
4. 5.993
The hydrated salt, Na2SO4.nH2O, undergoes a 55% loss in mass on heating and becomes anhydrous. The value of n will be:
1. | 5 | 2. | 3 |
3. | 7 | 4. | 10 |
12 g of Mg (atomic mass = 24) will react completely with an acid to yield:
1. One mole of H2
2. A half mole of H2
3. One mole of O2
4. None of the above